Castor is a temporal transcription factor that specifies early born central complex neuron identity

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Neuronal diversity is essential for brain function but incompletely understood.
• The Drosophila central complex (CX) provides a model system to study neuronal diversity generation.
• Type 2 neuroblasts (T2NBs) in the CX generate diverse neuronal types influenced by temporal gradients of RNA-binding proteins.

Purpose of the Study:

• To investigate the role of temporal transcription factors (TTFs) in specifying neuronal diversity within the Drosophila CX.
• To determine if TTFs with narrow expression windows contribute to CX neuron identity specification.
• To characterize the function of candidate TTFs in T2NB lineages.

Main Methods:

• Utilized Drosophila melanogaster as a model organism.
• Analyzed the developmental timing of neuron birth using larval T2NBs.
• Investigated the expression patterns of the candidate TTF Castor.
• Performed genetic experiments to assess the requirement of Castor in specifying neuron identities.

Main Results:

• Confirmed that adult E-PG neurons originate from early larval T2NBs.
• Demonstrated transient expression of the TTF Castor in early larval T2NBs during the birth of E-PG and P-EN neurons.
• Showed that Castor is essential for specifying the identities of early-born E-PG and P-EN neurons.

Conclusions:

• Castor functions as a temporal transcription factor in larval T2NB lineages.
• Castor specifies multiple, early-born CX neuron identities, contributing to neuronal diversity.
• This study elucidates a key mechanism in the generation of neuronal diversity in the Drosophila CX.